A team led by Caltech astronomers has discovered a new type of supernova that may burn 100 times brighter than typical exploding stars — and they're trying to figure out exactly how this new type works. The study, which identified four newly discovered supernovae as part of this unknown class, also solves the mystery behind two previously unexplained events — one that had been thought to be an extremely luminous Type II supernova, and another whose nature had scientists completely baffled.

Scientists have identified a type of supernova, or exploding star, that produces unusually large amounts of calcium — enough perhaps to explain the abundance of that element in the universe and in our bones. Perhaps more significant for astronomers, these calcium-rich exploding stars — eight have been identified so far — may also represent a new class of supernova, according to a study published Thursday in the journal Nature. "If it's not a new genus, it's at least a new species of supernova," said Alex Filippenko, a professor of astronomy at UC Berkeley and one of the study's 28 coauthors.

German astronomers using a U.S. telescope have provided scientists with at least a partial answer to a vexing question: What is the origin of the so-called Type 1a supernovae, which are widely used as celestial mileage markers? Type 1a supernovae are of special significance to astronomers because all are believed to have essentially the same intrinsic brightness, and because they can be observed from great distances. Thus, by comparing the brightness of any one of them to what it is expected to be, researchers can estimate its distance from Earth and thereby judge the distance of objects near it. Only a decade ago, astronomers used the supernovae to show that the expansion of the universe is accelerating, presumably due to the influence of so-called dark energy.

More than 400 years after Danish astronomer Tycho Brahe challenged established wisdom about the heavens by analyzing a strange new light in the sky, scientists say they've nailed down just what he saw. They knew the light came from a supernova, a huge star explosion. But what kind? A new study confirms that it was the common kind that involves the thermonuclear explosion of a white dwarf star with a nearby companion.

A pair of young astronomers have captured for the first time the earliest death throes of a supernova, verifying a decades-old theory about how the giant stars commit stellar suicide. While scanning a galaxy 90 million light-years away, the soon-to-be-married couple noticed a sudden eruption of X-rays from a spot in the constellation Lynx.

Astronomers have discovered the youngest known supernova in the Milky Way galaxy, still just a baby at 140 years old. The scientists, who announced their findings Wednesday, used a radio observatory in New Mexico and NASA's Chandra X-ray Observatory in space to determine when the supernova occurred. They dated the event to around 1868. Before this, the youngest supernova in the Milky Way was thought to have occurred around 1680. A supernova is the catastrophic explosion of a star that releases an extraordinary amount of energy, enough to outshine an entire galaxy.

Shining like a hay fire across a wide prairie, the brightest supernova ever recorded has been found in a galaxy 240 million light-years from Earth. Astronomers said Monday that the supernova might represent a new way for giant stars to die. "Of all the exploding stars ever observed, this was the king," said UC Berkeley astronomer Alex Filippenko. "We were astonished to see how bright it got, and how long it lasted."

There's enough Supernova for everyone. At least according to the settlement reached by an Orange County punk band called Supernova and the CBS reality show "Rock Star: Supernova." Under an agreement announced this week, the punk band will keep its name and the TV band will be known as "Rock Star Supernova."

IN the end, goth as much as rock won out in the finale of "Rock Star: Supernova," as Lukas Rossi -- the androgynous, spiky-haired Canadian wailer who favors charcoaled eyes, black nail polish and fingerless fishnet gloves -- beat all comers.

Astronomers have for the first time caught a supernova in the act of exploding, according to four papers this week in the journal Nature. NASA's Swift satellite first observed a gamma-ray burst Feb. 18 about 400 million light-years away toward the constellation Aries, and researchers began monitoring from observatories around the world. An initial burst of high-energy X-rays pierced the doomed star from its core before the massive star blew apart.